The present invention relates to a driving and supporting device for a transporting roller for textile fibers, in particular for a drawing roller of an open end spinning machine.
The drawing roller for an open end spinning machine guides the fiber material to be spinned to the machine. For transportation of the fibers, relatively high transfer forces are required. Also in rough spinning conditions, sporadically high radial and axial loads can occur during mounting, service or operation of the machine. The running accuracy of the drawing roller is decisive for the quality of the produced yarn. For the automatic spinning, a drive for the drawing roller which is independent from other parts, such as rotor drive and release roller, is of great advantage. As a rule, the drawing rollers of several spinning boxes have been centrally mechanically driven. An individual control of the individual drawing rollers of the spinning boxes is therefore however not possible. By means of an electrically controlled braking coupling, the drawing roller during the spinning process can be started, and in the event of a thread breakage, turned off.
Such a coupling however makes possible only two operational conditions: running with the rotary speed of the central drive or stopping. A stopping. A rotary speed regulation for example for spinning is not possible. Individual motor drives has been proposed for the drawing rollers, which are substantially flexible and with which high yam qualities could be realized. In the known individual motor drives, the drawing roller is supported on the drive shaft of the motor and thereby forces acting in the radial and axial direction on the drawing roller are completely transmitted to the motor bearing and their surface life is substantially limited. On the other hand, in the case of a separate mounting of shaft and motor they are coupled with one another. Such a coupling however occupies a substantial place. Moreover, the motor bearing remains loaded by transverse forces. The stepper motors are rigidly mounted on the machine. The vibration problems and the noise generation in the resonance region of the motor are a serious problem from the machines with 200-300 drive units.